The growth of data communication is reflection of modern life in the 21st century. Applications, such as e-mail and the Internet, have become a mainstream part of how people communicate. Data traffic has increased geometrically, perhaps, as acceptance and adoption of these communication forms continues to grow.
With the continued expansion of data applications, there is a growing consumer demand for accurate high-speed access. To support high-speed access, data communication systems presently employ any one of a number of distinct high-speed data communication formats or transport mechanisms. For the purposes of the present disclosure, a transport mechanism may include, for example, Asynchronous Transfer Mode (“ATM”), Internet Protocol (“IP”), Frame Relay (“FR”), Integrated Services Digital Network (“ISDN”), High bit-rate Digital Subscriber Line (“HDSL”), Asymmetric Digital Subscriber Line (“ADSL”), Very High Data Rate Digital Subscriber Line (“VDSL”), Symmetric Digital Subscriber Line (“SDSL”) 10 base T, 100 Base T, Gigabit Ethernet and E1/T1.
As the demand for communication networks and devices supporting each of the aforementioned transport mechanisms continues to expand, the issue of compatibility has arisen. More particularly, each transport mechanism has a set of different protocols and different transmission systems. Thusly, as connectivity grows, the complexity and cost of interfacing network and devices supporting differing transport mechanisms has also increased.
For example, ATM is a transport mechanism that may be suited to support circuit switched and/or packet switched connections. This flexibility may be built into a layer of the ATM Protocol, commonly known as the ATM Adaptation Layer (AAL). Currently there are four defined adaptation layers, commonly referred to as AAL1, AAL2, AAL3/4 and AAL5. While these adaptation layers are classified as ATM, each requires distinct equipment to interface between segments of the communications network, or, in the alternative, between communications network and an end user through a subscriber line, for example. Thusly, equipment supporting an AAL1 adaptation layer may not support the operation of an AAL5 adaptation layer.
One technique to address this growing compatibility issue is to require a physically different interface for each transport mechanism. Thusly, a network may have a distinct interface for each adaptation layer—e.g., a design for AAL1, AAL2, AAL3/4 and AAL5. This approach, however, may raise the cost of operation. Replacing interface cards in the network may require training and, therefore require increased the costs of maintaining the network.
Therefore, a need exists for one interface capable of supporting any one of a number of transport mechanisms that may reduce the cost of operation of the network, require less training and lower the cost of maintaining the network.